Shore-based Current Meters

This plot of wind driven ocean surface currents was created using shore-based high frequency radar. When two or more radar antennas are used, a scientist can calculate an entire field of surface current velocities. Using this data, the scientist can produce a map of surface currents for a large coastal area. The map consists of a series of different colored arrows. The direction of each arrow represents the direction that the current is moving, and the color of each arrow represents the current's speed at that particular location (red=fast, blue=slow.)